Transgenic technologies to induce sterility

The last few years have witnessed a considerable expansion in the number of tools available to perform molecular and genetic studies on the genome of Anopheles mosquitoes, the vectors of human malaria. As a consequence, knowledge of aspects of the biology of mosquitoes, such as immunity, reproduction and behaviour, that are relevant to their ability to transmit disease is rapidly increasing, and could be translated into concrete benefits for malaria control strategies. Amongst the most important scientific advances, the development of transgenic technologies for Anopheles mosquitoes provides a crucial opportunity to improve current vector control measures or design novel ones. In particular, the use of genetic modification of the mosquito genome could provide for a more effective deployment of the sterile insect technique (SIT) against vector populations in the field. Currently, SIT relies on the release of radiation sterilized males, which compete with wild males for mating with wild females. The induction of sterility in males through the genetic manipulation of the mosquito genome, already achieved in a number of other insect species, could eliminate the need for radiation and increase the efficiency of SIT-based strategies. This paper provides an overview of the mechanisms already in use for inducing sterility by transgenesis in Drosophila and other insects, and speculates on possible ways to apply similar approaches to Anopheles mosquitoes

Transgenic technologies to induce sterility

The last few years have witnessed a considerable expansion in the number of tools available to perform molecular and genetic studies on the genome of Anopheles mosquitoes, the vectors of human malaria. As a consequence, knowledge of aspects of the biology of mosquitoes, such as immunity, reproduction and behaviour, that are relevant to their ability to transmit disease is rapidly increasing, and could be translated into concrete benefits for malaria control strategies. Amongst the most important scientific advances, the development of transgenic technologies for Anopheles mosquitoes provides a crucial opportunity to improve current vector control measures or design novel ones. In particular, the use of genetic modification of the mosquito genome could provide for a more effective deployment of the sterile insect technique (SIT) against vector populations in the field. Currently, SIT relies on the release of radiation sterilized males, which compete with wild males for mating with wild females. The induction of sterility in males through the genetic manipulation of the mosquito genome, already achieved in a number of other insect species, could eliminate the need for radiation and increase the efficiency of SIT-based strategies. This paper provides an overview of the mechanisms already in use for inducing sterility by transgenesis in Drosophila and other insects, and speculates on possible ways to apply similar approaches to Anopheles mosquitoes

The value of the low-dose dexamethasone suppression test in the differential diagnosis of hyperandrogenism in women.

We studied 211 hyperandrogenic women with respect to clinical presentation, basal androgen levels, and the degree of cortisol and androgen suppression during a 48-h low-dose (2 mg) dexamethasone-suppression test (LDDST) to exclude ovarian and adrenal tumors. In 42 women with elevated testosterone levels, 21 of whom failed to suppress testosterone during the LDDST, the response of serum androgen levels during a 4-wk administration of 7.5 mg prednisolone in a reverse circadian regimen was also assessed. These results were compared with an additional 17 patients with histologically proven androgen-secreting tumors. Clinical presentation alone was suggestive of a virilizing tumor in 70% of patients with tumors. Serum testosterone, although occasionally only marginally elevated, was the sole androgen that was elevated in every patient with a tumor. After the LDDST, none of the patients with tumors obtained either a greater than 40% reduction or normalization of the previously elevated testosterone levels, whereas 88% of patients with nontumorous hyperandrogenism showed either normalization or suppression of more than 40%. With one exception, all of the patients with nontumorous hyperandrogenism who showed inadequate suppression of testosterone during the LDDST, and were treated with prednisolone, normalized the previously elevated androgens after 1 month of administration. In summary, in women presenting with hyperandrogenism, lack of testosterone suppression during the LDDST is associated with 100% sensitivity and 88% specificity in distinguishing patients with ovarian and adrenal androgen-secreting tumors from patients with nontumorous hyperandrogenism in this small series. The LDDST is an easy to perform screening test that can also identify causes of hyperandrogenism due to altered glucocorticoid secretion

SBFT: a Scalable and Decentralized Trust Infrastructure

SBFT is a state of the art Byzantine fault tolerant state machine replication system that addresses the challenges of scalability, decentralization and global geo-replication. SBFT is optimized for decentralization and is experimentally evaluated on a deployment of more than 200 active replicas withstanding a malicious adversary controlling f = 64 replicas.Our experiments show how the different algorithmic ingredients of SBFT contribute to its performance and scalability. The results show that SBFT simultaneously provides almost 2x better throughput and about 1.5x better latency relative to a highly optimized system that implements the PBFT protocol.To achieve this performance improvement, SBFT uses a combination of four ingredients: using collectors and threshold signatures to reduce communication to linear, using an optimistic fast path, reducing client communication and utilizing redundant servers for the fast path.SBFT is the first system to implement a correct dual-mode view change protocol that allows to efficiently run either an optimistic fast path or a fallback slow path without incurring a view change to switch between modes

The Relationship Between Hospital Stroke Center Designation and TVT Reported Stroke: The Michigan TAVR Experience

BACKGROUND: The 30-day rate of stroke after transcatheter aortic valve replacement (TAVR) has been suggested as a hospital quality metric. Thirty-day stroke rates for nonsurgical, high, and moderate-risk TAVR trials were 3.4% to 6.1%, whereas those in the national Transcatheter Valve Therapy (TVT) Registry for the same patient population were much lower. Hospital comprehensive stroke center (CSC) is the highest designation for integrated acute stroke recognition, management, and care. OBJECTIVES: Using Michigan TVT data, we assessed whether in-hospital post-TAVR stroke rates varied between CSC and non-CSC institutions. METHODS: TVT data submitted from the 22 Michigan Transcatheter Aortic Valve Replacement Collaborative participating institutions between January 1, 2016, and June 30, 2019, were included (N = 6,231). Bayesian hierarchical regression models accounting for patient clinical characteristics and hospital clustering were fitted to assess the association between hospital CSC accreditation and in-hospital post-TAVR stroke. Adjusted ORs and 95% credible intervals were estimated. The University of Michigan Institutional Review Board has waived the need for the approval of studies based on the data collected by the Blue Cross Blue Shield of Michigan Cardiovascular Consortium registry. RESULTS: There were 3,882 (62.3%) patients at 9 CSC sites and 2,349 (37.7%) patients at 13 non-CSC sites. CSC sites had significantly higher rates of in-hospital post-TAVR stroke (CSC: 2.65% vs non-CSC: 1.15%; P \u3c 0.001). After adjustment, patients who underwent TAVR at a CSC hospital had a significantly higher risk of in-hospital stroke (adjusted OR: 2.21; 95% CI: 1.03-4.62). However, CSC designation was not significantly associated with other important post-TAVR clinical outcomes including 30-day mortality. CONCLUSIONS: Reported Michigan Transcatheter Aortic Valve Replacement Collaborative TVT stroke rates were significantly higher at sites with Joint Hospital Commission stroke designation status; however, other reported important clinical outcomes did not differ significantly based on this designation. CSC designation is a possible factor in stroke rate detection differences between TAVR institutions and might be a factor in the observed differences in stroke rates between TAVR trials and those reported in TVT. In addition, these data suggest that comparison between hospitals based on post-TAVR stroke rates is potentially problematic

Pharmacists' knowledge, perspectives, and experiences with mifepristone dispensing for medication abortion.

BackgroundThe U.S. Food and Drug Administration (FDA) restricts dispensing of mifepristone for medication abortion to certified health care providers at clinical facilities, thus prohibiting pharmacist dispensing. Allowing mifepristone dispensing by pharmacists could improve access to medication abortion.ObjectiveTo assess the feasibility of pharmacists dispensing mifepristone to patients who have undergone evaluation for eligibility and counseling for medication abortion by a clinician.MethodsBefore providing a study training on medication abortion, we administered baseline surveys to pharmacists who participated in a multisite mifepristone-dispensing intervention. The survey assessed medication abortion knowledge-using a 15-item score-and perceptions about the benefits and challenges of the model. We administered follow-up surveys in the study's final month that also assessed the pharmacists' satisfaction and experiences with mifepristone dispensing. To investigate the association of the study intervention with the pharmacists' knowledge, perceptions, and experiences dispensing mifepristone, we conducted multivariable linear regression analyses using generalized estimating equation models, accounting for clustering by individual.ResultsAmong the 72 pharmacists invited from 6 pharmacies, 47 (65%) completed the baseline surveys, and 56 (78%) received training. At the study's end (mean 18 months later), 43 of the 56 pharmacists who received training (77%) completed the follow-up surveys. At follow-up, 36 (83%) respondents were very or somewhat satisfied with mifepristone dispensing, and 24 (56%) reported experiencing no challenges dispensing mifepristone. Four (6%) of the 72 pharmacists invited objected to participating in mifepristone dispensing. In regression analyses, average knowledge scores, perceived ease of implementation, and level of support for the pharmacist-dispensing model were higher at follow-up (P < 0.001).ConclusionMost pharmacists were willing to be trained, dispensed mifepristone with few challenges when given the opportunity, were satisfied with the model, and had higher knowledge levels at follow-up. Our findings support removal of FDA's restriction on pharmacist dispensing of mifepristone